Re: [RFC PATCH 02/34] ARM: mm: make 2-level pgd_t a scalar
"David Hildenbrand (Arm)" <[email protected]> Tue, 14 Jul 2026 15:03:28 +0200
| Newsgroups | org.kernel.vger.linux-csky,dev.linux.lists.loongarch,org.infradead.lists.kvm-riscv,org.infradead.lists.linux-riscv,org.kernel.vger.linux-arch,org.kernel.vger.linux-kernel,org.kernel.vger.linux-m68k,org.kernel.vger.linux-mips,org.kernel.vger.linux-openrisc,org.kvack.linux-mm |
|---|---|
| Message-ID | <[email protected]> |
On 7/14/26 14:34, David Laight wrote: > On Mon, 13 Jul 2026 14:55:41 +0100 > Yeoreum Yun <[email protected]> wrote: > >> From: "David Hildenbrand (Arm)" <[email protected]> >> >> We don't want pgd_t to be an array, as it prohibits returning it from a >> function, like pgdp_get(). > > If you use a two element structure the compiler/ABI might be able to > return that from a function in two registers. > That might make the entire mess more readable ... The patch description states: " As an alternative, we could use the STRICT_MM_TYPECHECKS approach here as well, but using an u64 looks conceptually cleaner, even though pgd_val() gets a bit more involved. " Arnd replied on that in more detail. Maybe I should just go back to using bit shifts and handing endianess. -- Cheers, David